Evaluation of solar sludge drying alternatives on costs and area requirements

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Bilimleri Enstitüsü, Fen Bilimleri Enstitüsü, Türkiye

Tezin Onay Tarihi: 2014

Öğrenci: Mayıs Kurt

Asıl Danışman (Eş Danışmanlı Tezler İçin): AYŞEGÜL AKSOY

Eş Danışman: FAİKA DİLEK SANİN

Özet:

There are basically two common sludge drying methods, thermal drying and solar drying. While thermal drying requires high amount of energy, solar drying cannot typically attain the 90 % DS requirement. The literature studies emphasize the benefits of solar drying used as GSD (greenhouse solar dryer) to reduce energy requirement but these dryers cannot achieve 90 % DSC without any auxiliary heat. Therefore, use of solar panels as auxiliary heat source was evaluated in this study. To calculate how much energy and area is required in the drying system, an optimization problem was written. Area limitation was used as a constraint in this optimization problem. The results showed while DSm ratio is 70 % DS, the total cost was minimum. On average, 58 % of the total cost and 38 % of total required area consisted of GSD cost and the rest was solar panel cost. The area is important parameter to reach high DSC. WWTPs (waste water treatment plants) whose sludge flow rate is higher than 5 ton/hr are not suitable for GSD due to area limitation. Although GSD with solar panels has high investment cost, it is more economical than thermal dryers for long term energy requirement. To conclude, this study demonstrates that solar panels can be used as auxiliary heat source for a GSD instead of a thermal dryer if enough area, solar radiation, ventilation and mixing of sludge is provided.